Sunday, September 20, 2015

Early: autumn

After record-setting regional heat and a dry spring and summer, the early onset of cool and wet weather is a nice surprise!  This usually occurs in October around here but September has had several weak storms dampen gardens (and better still, forest fires!).  The dry weather is most often July through early October here, and 90° temps in Portland can happen through most of September. This year it would take quite a turnaround to reach even the mid-80s, though it's possible. I turned on the furnace around the 15th, so it's beautiful time to get the wood stove ready for another season. Thankfully the chimney is swept so I won't be working on a slick roof!

Maybe this year we'll see some snowit would be fun.. for a few days at least!


One interesting item about snow: Portland often gets bitter east winds through the Gorge which can freeze (or re-freeze) precipitation in the cold season.  We're further away from that effect now, and around two sharp curves.  Also valuable is that we're 800 feet up; the Arctic air will have to flow further to reach us and its effects are at the very lowest elevations since cold air sinks.  We may well stay out of the bad winter weather that I've spent my lifetime seeking (or avoiding if I must travel in it).  Huge east winds often produce sleet and freezing rain in Portland.. maybe not so much here?

The easterly winds still reach us: we had many hot summer days here when east winds passed over the Cascade crest and down to our homestead.  This will provide cold air and snow now and then - but since the coldest air prefers the 100-foot high gap by Portland to jumping the 3000-foot crest, we could see fewer sleet and z-rain events.  It may take a few years to demonstrate this though!

I recently found the PRISM website at Oregon State University, where regional climate normals can be found - and they are calculated in very small areas.  I narrowed down to my site and learned that we can expect just under  64" of precipitation each year.  That's quite a jump over Portland's sub-40" total, though not a surprise. Portland has the west hills and coast range to buffer it from the dominant westerly flow, while we're right up the funnel of the Columbia estuary.  We have been here for over a year now, but the weather system has not been up long enough for me to see how we've measured up.  Since April though I'd say "DRY" since no month since has seen 0.92" like our driest month should be!




No comments:

Post a Comment